Packaging for bitumen

ABSTRACT

A consumable bitumen packaging compound including at least one packaging material/s, such as polymers, plastics and extenders and the like, used in combination with the bituminous material and a metal, either pure in powder form or in the form of salt or oxide, that is physically and/or chemically combined with the polymer material, so that the density of the packaging material is adjusted to prevent the material from floating to the surface of the molten material after melting. The components of the packaging are preferably selected such that they are compatible with the bitumen. After transport and storage, the packaging material can therefore be directly incorporated into the bitumen product for final use, such that the formation of a polymer skin accumulating at the surface of the molten material is largely avoided.

TECHNICAL FIELD

The invention relates to a consumable product packaging compoundcomposed of at least one packaging material, such as polymers, plasticsand extenders and the like, used in combination with bituminousmaterial. The packaging compound comprises a dense metallic material,either pure in powder form or in the form of salt or oxide that isphysically and/or chemically combined with the packaging material, sothat the density of said material is adjusted to prevent the materialfrom floating to the surface of a mixture of bituminous product andpackaging material upon melting of the bituminous product or in themolten bituminous product after melting. The components of the packagingmaterial are preferably selected such that they are compatible with abituminous product to be packaged. After transport and storage, thepackaging material can be directly incorporated into the bituminousproduct for final use without formation of a film (or “skin”) thataccumulates at the surface of the molten material during a melt process.

BACKGROUND ART

Bitumen products (also known as asphalts), tars or resins are well knownmaterials used in many road building, construction, and other industrialapplications. The characteristic that bitumen products have in common isthat they are solid or semi-solid at ambient temperature and liquid atelevated temperatures. For transportation from source to end-uselocation, these materials are either carried in bulk or in containers.When carried in bulk, they should be maintained at such a temperaturethat their viscosity is low enough to allow for easy pumping andtransfer thereof. When carried in containers, such as drums or pails ofany size and shape, their temperature, after filling, drops to ambientand the product becomes solid or semi-solid. The containers aregenerally transported and stored at ambient temperature. Before use, thecontainers and the material they contain have to be heated-up or meltedto allow for the pouring, pumping and transfer of the product. Afterheating, the container usually cannot be reused and must be disposed of.

Bitumen product containers have to be solid enough for handling andtransport, and have to be able to be heated up before the product can beused. For this purpose, they are usually made of metal, most commonlysteel, and are in the form of drums. The main advantage of steel drums,compared with other types of similar packaging, is that they arerelatively inexpensive. There are, however, at least three problemsassociated with using drum containers. The first is that the drumcontainers have to be disposed of after use. As they contain bitumenproduct, it is almost impossible to clean them up for re-use and theytherefore become waste. The second is that, owing to the relatively highviscosity of bitumen products, it is practically impossible to empty thedrums totally. As a result, it is usually considered that up to 2 to 3%of the product left adhering to the walls of the container is lost. Thisincreases the amount of wastage material released into the environment.The third problem relates to transport cost and efficiency. Due to theloss of usable amount of bitumen products through its adherence to thecontainer walls, this results in the need for an overestimation in theactual and final useable weight of bitumen products. Accordingly, tomake up for the shortfall of useable bitumen one has to increase thevolume of product ordered, which increases the total weight of productrequired to be transported.

To solve the problem of wastage and freight burden, a number ofsolutions have been proposed, and a number of them utilizing soft bagpackaging as the container. In these cases, the bitumen product ispacked, while hot, into soft bags. Upon cooling down, the bitumenproduct becomes solid or semi-solid at ambient temperature, as does thewhole of the package. Bags can then be handled, stored, transported tothe end-use location with freight burden kept to minimum. The use of apolypropylene film to package roofing asphalt has also been described(see U.S. Pat. No. 5,452,800).

While the solution of using plastic bagging or film addresses one of theproblems associated with steel drum packaging, it is in itself a sourcefor other problems. The two main reasons relate to the density and thento the compatibility of the container material with the bitumencontained therein. As mentioned, bitumen products are required to bemolten before transfer and use. The plastic in contact with the bitumenproduct cannot be removed, as it is firmly adhered to the outside of theproduct. In order to access the bitumen product, it therefore has to bemelted together with its packaging.

The plastic is usually designed to melt at the melting temperature ofthe bitumen product. However, this does not necessarily mean that theplastic is compatible with the bitumen product. Plastic or polymerproducts, such as those used in the packaging industry, likepolyethylene, polypropylene, polystyrene, etc., are not easily dispersedin bitumen products. Not only does it take quite a lot of shearingenergy to achieve dispersion, but it also requires the materials to bechemically compatible with each other. As a result of incompletedispersion throughout the bitumen product, and due to the lower densityof the plastic or polymer materials compared with that of bitumen, theplastic materials like polyethylene, polypropylene, and polystyrenemigrate towards the surface of the melting or molten bitumen material.Over time, a film, or skin, of the plastic material so formed thickensand rapidly becomes a source for severe operational problems.Interestingly, however, the formation of this film has been viewed as abeneficial outcome in that it is able to reduce the emission of fumesfrom asphalt materials during the melting process (see U.S. Pat. Nos.5,733,616; 5,989,662; and 6,107,373, which, in addition to describingthe use of solid containers that melt with asphalt, even describe theintentional addition of polymer material to molten asphalt to form askin to reduce fumes). See also WO 00/55280.

However, road-paving bitumens, having a significantly lower softeningpoint, are much softer than roofing bitumens. Road-paving bitumens aretherefore used and handled at significantly lower temperatures in such away that fumes generated during storage is of much less concern thatwith roofing bitumens. In addition, roofing bitumen is heated up on siteand used in relatively small quantities, whereas road-paving bitumen isused in much larger quantities and stored in tanks of considerable size.A skin of polymer materials generated by the packaging materials forbitumens, as described above, would be undesirable in most cases of roadpaving bitumen melting and storage. The high viscosity and low densityof such a polymer skin would make it very difficult to remove or toconsume. The skin would also arguably increase in thickness at thesurface of a tank or other container with each load and over time,become too thick and therefore impossible to remove. Additionally,road-paving bitumens, unlike roofing bitumens, still flow at ambienttemperature. This makes them more difficult to package in suitablepackaging material than roofing bitumen.

In order to reduce the problem of polymer skin formation at the surfaceof the molten bitumen material, several options have been proposed likereduced packaging thickness or the use of double layer packaging. In thecase where the packaging material is kept thin, such packaging becomessensitive to puncturing and damage during transport. This, in turn,results in leaks with all the associated spillage problems. As a result,the main container containing bags of bitumen products in thin bags canbe badly dirtied and a large part of the cargo can be spoiled with bagsbeing glued to each other. Also, and in the case of double layerpackaging, the outer layer has to first be peeled off and disposed ofbefore the melting process can take place. Peeling off the outer layercan prove to be very difficult due to the thinness of the inner layer,which frequently results in leakage of small amounts of bitumen productinto the space between the outer and inner layers. This makes thepeeling off of the outer layer impossible in extreme cases. This resultsin more packaging (from the thicker outer layer) accumulation at thesurface of the molten bitumen, causing associated operational problems,like product homogeneity, pumping, pipe clogging, etc.

Modification of the characteristics of bitumen products by the additionof polymers or plastic components is a well-known field of technologyand this has been described and discussed in many publications, atinternational conferences, and in the internal publications of severalcorporations. In the field of bitumen technology, and as reported inpublications from the ASTM and the European Asphalt PavementAssociation, it is today widely accepted that polymers and plastic donot readily blend with bitumen products, and that a mixing process usingshearing energy and compatibilization time is required before all thecomponents form an intimate blend.

Citation of the above documents is not intended as an admission that anyof the foregoing is pertinent prior art. All statements as to the dateor representation as to the contents of these documents is based on theinformation available to the applicant and does not constitute anyadmission as to the correctness of the dates or contents of thesedocuments.

Disclosure of the Invention

There is a definite need for bitumen product packaging that is strongenough for ease of handling, transport and storage. Such packagingshould be economical enough to compete against other types of packagingand should preferably incur little or no release of wastage into theenvironment. It should ideally be compatible with the material containedwithin it. More importantly, the packaging material should have a higherdensity than that of the contained material in order to preventformation of a skin at the surface of storage and/or heating tanks, thusfacilitating subsequent heating and melting processes.

The present invention provides a composition which may be used as apackaging material for bitumen products. The composition is composed ofpolymer material combined with a bituminous material and a densityincreasing metallic charge. The polymer material is preferablycompatible with the bitumen product to be packaged. The metallic chargeis preferably at least one metal or the oxide or salt thereof, inpowder, salt, or oxide form.

With a higher density than that of the packaged material, the packagingmaterial sinks downwards as the packaged material melts during a heatingprocess. As the heating process progresses until all material is molten,the packaging material slowly releases its metallic charge as it meltsand combines with the packaged bitumen material. The time intervalbetween reaching the melting temperature and the final molten state ofthe packaging allows the packaging material to swell and becomeincorporated within the contained material. Optionally, the melting ormolten material may be mixed to increase the dispersion of the packagingmaterial. The quantity of non-incorporated packaging material migratingto the surface is minimized, while the minimal amount of packagingresidue accumulates at the bottom of the vessel may be flushed andfurther attempts at incorporating it into the packaged material duringrecycling, pumping and transfer of the final product can be made.

Therefore, and in a first aspect, the invention provides a compositionfor forming containers or wrappings for bitumen products, saidcomposition comprising (i) 60.1% to 99.9% by weight of a moldablematerial composed of a plastic or polymer material wherein 0.1% to 39.9%of said 60.1% to 99.9% is bituminous material; and (ii) 0.1% to 39.9% byweight of a dense metallic material.

Bituminous material refers to matter composed of much organic, and/orcarbonaceous, substances that are mostly in the form of tarryhydrocarbons. The material is usually soluble in carbon disulfide, andincludes bitumen products. A “bitumen product” as used herein isemployed to mean naturally occurring or heat refined substances that arecomposed mainly of carbon and hydrogen with little oxygen, nitrogen orsulfur. They are usually dark brown or black mixtures of hydrocarbonssuch as asphalt, crude petroleum, or tar. The term thus includes naturalor synthetic heavy petroleum or tar-derived products as well as roadpaving bitumens, blown or oxidized bitumens, roofing bitumens,polymer-modified bitumens, naturally occurring bitumens, refinery bottomresidues, de-asphalting rocks, petroleum-tars and coal-tars. The termalso encompasses raw or processed asphalt, including asphalt bottomsfrom petroleum refineries, naturally occurring bituminous materials,tars and pitches, or the air-blown or chemically processed or treatedforms of these same materials. Non-limiting examples include air blownasphalt containing catalysts such as ferric chloride, as well asconventional roofing flux asphalts or paving-grade asphalts or specialtyasphalts like water-proofing asphalts and sealers. The invention mayalso be practiced with blends of different kinds of asphalt or otherbitumen products. A bituminous material can be used in pure form or in achemically modified form.

The metallic material may be any source of metal ions derived from atleast one metal or the salts and oxides thereof. Alternatively, it maybe a metal complex composed of a metallic material that has beencombined with a plastic or polymer material.

The composition optionally further comprises an extender which maintainsthe relative amounts of the moldable material and density increasingmetallic material. Non-limiting examples of such extenders includeantioxidants, UV stabilizers, surfactants, binders, colourants, andmixtures thereof.

In a particular embodiment of the invention, a composition comprising(i) about 90% by weight of a moldable material composed of about 83% ofethylene-vinyl-acetate copolymer a plastic or polymer material and about17% of bituminous material; and (ii) about 10% by weight of iron oxideis provided.

Another aspect of the invention relates to the use of the compositionsof the invention as packaging materials. Preferably, the density (orspecific gravity) of the composition, and thus packaging material, isgreater than the density of the material packaged therein. In oneembodiment, the compositions of the invention are used to produceconsumable containers as packaging material for use in transport and/ormelt-processing operations, particularly of bitumen products. Suchcontainers may be in any suitable shape or size, including, but notlimited to a sealable bag, barrel, box, bowl, or cylinder. Thecontainers may be prepared by any suitable process, including, but notlimited to blow-molding, casting, injection molding, the use of aforming apparatus, or combinations thereof. The compositions of theinvention may also be used to make films of various thicknesses andsuitable for packaging.

Compared with previously used packaging material and processes forpackaging of bitumen products, the disclosed invention provides theadvantages including the following. In the case of packaged bitumenproducts, the higher density of the packaging material relative to thepackaged bitumen products reduces non-molten packaging material leftfloating in heating vessels. This provides the benefit of avoidingsubsequent operational problems. Also, the presence of bituminousmaterials in the packaging material can allow it to ultimately becomeincorporated into the packaged bitumen products. Wastage and extrafreight burden on shipment due to the packaging material can be reduced.

Moreover, the bituminous materials can be “pre-blended” in preparing thecompositions of the invention such that the resultant packagingmaterials are “pre-compatibilized” for dispersion into a bitumen productduring a melting process. The “pre-blended” or “pre-compatibilized”material allows for the design of thicker walled containers and films,as well as reinforcement structures within said containers, withvirtually no risk of finding thicker, non-dissolved or non-molten piecesof packaging material during a heating and melting process. Thicker andstronger packaging materials permits safer handling and longer storagetime as well as reduced risk of punctures and subsequent leakage.

Generally, the ability of the compositions of the invention to be usedin consumable packaging materials for bitumen products reduces the needto dispose of used packaging materials, with any residual amounts ofbitumen products, into the environment.

In a further aspect of the invention, methods are provided for theproduction of compositions as disclosed herein.

Modes of Carrytin out the Invention

The invention provides compositions of modified plastic or polymermaterials that contain a density increasing metallic material toincrease the specific gravity of the composition relative to the plasticor polymer materials. The plastic or polymer materials are blended withthe density increasing metallic material as described herein or viamethods known in the field. Preferably, the metallic materials increasethe specific gravity of the composition to be about 5%, about 10%, about15%, about 20%, about 25%, about 30%, or about 35% or more than thespecific gravity of a bitumen product of interest for packaging.

Generally, the plastic or polymer material used in the practice of theinvention is any that is compatible with the material to be packaged andthat is suitable for use as packaging material formed from thecompositions of the invention. The compositions of the invention havethe necessary physical properties such that packaging materials formedtherefrom have the required toughness, impact resistance, temperaturestability, and/or flexibility.

Exemplary plastic or polymer materials for use in the practice of theinvention include, but are not limited to, ethylene, propylene,ethylene-propylene copolymers, and butylene copolymers. Alternatively,copolymers of acrylates and methacrylates, such as butyl, propyl, ethyl,or methyl acrylate or methacrylate copolymerized with ethylene,propylene, or butylene, may also be used. Epoxy-functionalizedcopolymers such as a terpolymer of ethylene, butyl acrylate and glycidylmethacrylate may also be used to improve the impact-resistance andflexibility of packaging materials made thereof. Natural or syntheticrubbers may also be used; non-limiting examples includestyrene-butadiene-styrene (SBS), styrene-butadiene rubber (SBR),styrene-ethylene-butylene-styrene (SEBS), or terpolymer made fromethylene-propylene diene monomer (EPDM). In one embodiment, the materialincludes an ethylene-vinyl acetate copolymer with a vinyl acetatecontent from about 5% to about 40% by weight, so that it is soluble inasphalt or other bitumen products. Mixtures of the above materials mayalso be used.

Particularly preferred plastic or polymer materials for use in theinvention are selected from polyethylene, polypropylene, polystyrene,styrene-butadiene-styrene, styrene-butadiene, styrene-indene-styrene,copolymers of acrylates and methacrylates, ethylene-vinyl-acetate,atactic polypropylene, mineral or natural or synthetic fibers, andmixtures thereof. Ethylene-vinyl-acetate is especially preferred in thepractice of the invention. In some embodiments of the invention, thematerial is a random copolymer of ethylene and unsaturatedmonocarboxylic acid that is neutralized with a metal ion, but theinvention may be practiced without the use of plastic and polymermaterials other than this neutralized copolymer.

The density increasing metallic material of the compositions ispreferably a source of metal ions derived from at least one metal or thesalts and oxides thereof. The material is preferably in the form of apowder, pellet or granule that can be blended with the plastic orpolymer material used. The metallic material preferably comprises iron,calcium, zinc or silicon, although many other density increasing metalsmay be used. Preferred metallic materials include iron oxide, calciumcarbonate, a silicate, zinc sulfate, or mixtures thereof. Especiallypreferred is the use of iron oxide. Other materials, such as crushedstone or glass fibers may also be used. Particularly preferred in thepractice of the invention is any metallic material suitable to bepresent in a bitumen product to be packaged. Also preferred are metallicmaterials with high specific gravity, such as at least 2.7 (calciumcarbonate) or at least 5.0 (iron oxide).

The bituminous material present in the compositions may be a bitumenproduct as described herein. It may also be a semi air-blown bitumen oroxidized bitumen, such as bitumen used for roofing and waterproofingapplications. It may be advantageous to maximize the amount ofbituminous material in the compositions of the invention where they areof a lower cost than the plastic or polymer materials. Similarly, theamount of metallic material may be minimized to only that necessary toproduce a composition having a slightly higher specific gravity than abitumen product to be packaged.

The compositions of the invention may be formed into a variety ofpackaging materials, including containers of various shapes and sizes.Examples of possible containers include those described in U.S. Pat.Nos. 5,733,616; 5,989,662, and 6,107,373. Other possible containers arethose described in published applications WO 98/39221, WO 99/30973, andWO 00/55280.

The compositions may also be formed into sealable bags or films likethat described in U.S. Pat. No. 5,452,800 for use in packaging. Thethickness of such bags or films may be readily determined by the skilledperson depending on the application to which the bags or films are to beused. Thicknesses of at least about 0.1 to 5 mm are within the scope ofthe invention.

The compositions, when used as a packaging material, should have asoftening point high enough to tolerate the temperatures of a moltenbitumen product. Preferably the material has a ring and ball softeningpoint higher than about 70° C., more preferably higher than about 90°C., and even more preferably higher than about 110° C. The ring and ballsoftening point may be measured by ASTM D36.

A container of the invention may be formed by any convenient process.Without limiting the invention, the sidewalls of the container can bebonded to the base. In preferred embodiments, the container is formed asan integral or unitary structure by injection molding, blow molding,rotation molding, or other molding processes. As known to the skilledperson, a molding process usually involves the use of a heat-softenedcomposition to be molded. The heat-softened composition is injected,blown, or otherwise formed via a mold into a desired shape and size.After cooling and solidification, the composition takes the shape of themold cavity.

The containers of the invention can also be adapted to have handholds,breakaway sections, recesses, and ribs to increase its strength. Theribs may be internal or external to the container and may also serve toprovide stability of shape to the container. The container should havesufficient strength to support molten bitumen product without tearing orsignificant yielding.

As noted herein, the packaging materials of the invention are consumablesuch that they would be incorporated into the packaged bitumen productupon its heating or melting. Advantageously, the packaging materials ofthe invention have a higher specific gravity than the packaged bitumenproduct such that the materials do not “float” to the surface of theproduct upon heating. The materials are not “buoyant” in a melted ormolten bitumen product. This facilitates the dissolution and dispersionof the packaging materials into the heated bitumen product.

The packaging materials are preferably used to contain bitumen productsas described herein. Non-limiting examples of such products includeasphalt, asphalt bottoms from petroleum refineries, naturally occurringbituminous materials, tars and pitches. They can also be a conventionalroofing flux asphalt, a paving-grade asphalt, water-proofing bitumen,battery compounds, and sealers. These products may be air-blown orotherwise chemically processed or treated. For example, the asphalt canbe air blown with catalysts such as ferric chloride and the like.

In one embodiment of the invention, the packaging materials and asphaltcontained therein has a solubility in trichloroethylene of at least 99%such that it meets most international standards for bitumen. The amountof metallic material in the packaging material would thus be no morethan 1% of the total weight of packaging materials and asphalt.

The compositions and packaging materials of the invention may be“pre-blended” with bituminous material to improve their dissolution inbitumen products upon heating or melting. “Pre-blending” refers to theincorporation of bituminous material into the compositions and packagingmaterials before the latter are to be dispersed into the packagedbitumen products.

The compositions of the invention are readily prepared by combining aplastic or polymer material with bituminous and metallic materials asdescribed herein and/or by standard methods in the field. Thecombination is preferably heated, and mixed or blended, to form ahomogenous composition comprising all three materials. This blendedmaterial may be used directly to form packaging materials of theinvention or cooled for later use to prepare packaging materials.

The compositions and packaging materials of the invention preferably donot significantly alter the characteristics of a bitumen productpackaged therewith after the compositions and packaging materials aredispersed into the product. As non-limiting examples, bitumen productscontaining the dispersed composition or packaging material differ fromthe same bitumen product without the dispersed material by not more thanabout 3 to about 5% in penetration (by 0.1 mm increments) at 25° C. asdetermined by ASTM D5; by not more than about 3 to about 20% insoftening point temperature as determined by ASTM D36; by not more thanabout 3 to about 10% in viscosity (by cSt) as determined by ASTM D445;by not more than about 3 to about 10% in ductility (by cm) as determinedby ASTM D13; and by not more than 1% in trichloroethylene solubility (by%) as determined by ASTM D2042.

In accordance with a particularly preferred embodiment of the invention,the composition of the packaging material is first designed to becompatible with the contained bitumen product and in a form suitable forits final intended use. The density of the packaging material isadjusted by means of increasing or decreasing the amount of metallicmaterial added, such the density is higher than that of the material tobe packaged. The amount of metallic material may be added in relativelysmall amounts in comparison to the amount of packaging material. Asthere is provision in most paving bitumen for a maximum allowable limitof 1% by weight of insoluble matter, the amount of metallic chargeshould remain below this limit in the final molten bitumen. Thepackaging material would normally not xceed 5% by weight of the totalpackaged product, most preferably about 3%. Therefore, there issufficient flexibility to adjust the content of metallic charge toensure that it does not exceed 1% of the total weight of the packagedmaterial.

The components of the packaging material are proportioned and blendedtogether at the suitable temperature to allow for efficient mixing ofall components. After mixing and homogenization, the packaging mixtureis then processed through package forming devices, such as a blowing orfilm blowing machine, an injection molding machine, a casting device ora forming machine to produce containers of the desired form and shape.The size and shape of the containers may take into account logisticsconstraints and economical considerations. The molten bitumen product issubsequently packaged in the produced containers using any suitablefilling device and allowed to cool therein.

In a preferred practice of the invention, the polymer or plasticcomponent of the packaging composition is made of bitumen compatiblepolymer such as ethylene-vinyl-acetate or styrene-butadiene-styrenewhich has been pre-blended with bituminous material or derivativesthereof, such that it is compatible with the bitumen product to bepackaged. The bituminous material can be bitumen of the same or of adifferent penetration grade than the bitumen product to be packaged. Thegrade of paving bitumens is generally determined by the penetrationtest, such as the ASTM D-5 method. The grade is given as the depth intenths of millimeters of penetration of a needle at 25° C., during 5seconds and with a load of 100 grams. Typical paving grades are:5/15-20/30-40/50-50/70-60/70-60/80-80/100-180/220-300/400. The grade ofoxidized bitumen is generally determined by the ring and ball softeningpoint test, such as the ASTM D36. Typical oxidized grades are:75/30-85/25-100/40-125/30.

Non-limiting examples of bituminous material are oxidized bitumen,semi-blown bitumen, naturally occurring bitumen, refinery heavyresidues, heavy fuel-oil, extracts, petroleum-tar, coal-tar, aromaticextracts, synthetic or natural resins, and mixtures thereof.

Definitions of Terms Used herein

As used herein, the terms “comprise”, “comprises”, “comprised” or“comprising” are to be interpreted as specifying the presence of thestated features, integers, steps or components referred to, but not topreclude the presence or addition of one or more other feature, integer,step, component or group thereof. Stated differently, and as usedherein, the term “comprising” and its cognates are used in theirinclusive sense; that is, equivalent to the term “including” and itscorresponding cognates.

As understood generally, “density” is used herein to refer to themeasure of the mass of a unit volume of a substance. It is thus“volumetric density” as opposed to “linear density” or “area density”.

“Specific gravity” as used herein refers to “relative density” or ameasure of how the density of one substance compares with another. The“other” substance is most often pure water, with a density of 1 kg perliter. “Specific gravity” has no units because it is a ratio of twodensities.

Unless defined otherwise all technical and scientific terms used hereinhave the same meaning as commonly understood to one of ordinary skill inthe art to which this invention belongs.

The following examples are put forth so as to provide those of ordinaryskill in the art with a complete disclosure and description of how tomake and use the present invention, and are not intended to limit thescope of what is regarded as the invention nor are they intended torepresent that the experiments below are all and only experimentsperformed. Efforts have been made to ensure accuracy with respect tonumbers used (e.g. amounts, temperature, etc.) but some experimentalerrors and deviations should be accounted for. Unless indicatedotherwise, parts are parts by weight, molecular weight is weight averagemolecular weight, temperature is in degrees Celsius, and pressure is ator near atmospheric.

EXAMPLE 1 Preparation of Packaging Material for a Bitumen Product

A packaging material for bitumen product was prepared as follows.

The packaging material was composed of 90 wt % of a mixture composed of8.3 parts of ethylene-vinyl-acetate copolymer, having a melt-flow indexof 8 (g/10 min) and 1.7 parts of bitumen having a penetration of 60/701/10mm at 25° C., and 10 wt % of industrial grade iron oxide in finepowder form. After thorough blending at 200° C. of the components forabout 1 hour, the packaging material was manually formed intocylindrical containers in molds of approximately 3 liters capacity.Thickness of the containers were designed such as the total quantity ofpackaging material was approximately 2.5 wt % of the total gross weightof the final packaged material.

The specific gravity at 25° C. of the components was: Standard bitumen60/70 penetration grade 1.03 Ethylene-vinyl-acetate, 8 MI 0.94 Ironoxide, approx. 5.0 Theoretical specific gravity of packaging material at25° C. 1.36 Measured specific gravity by hydrostatic balance at 25° C.1.08

Without being bound by theory, the difference observed betweentheoretical density and measured density is believed to be due to(micro) air bubbles trapped into the packaging material duringpreparation. While this air was not removed in this simple process atlaboratory scale, they may be readily removed or reduced by use ofindustrial processes, including molding or injection processes, underhigh pressure.

The specific gravity of the packaging material was therefore higher thanthat of bitumen product. As such, the material is not buoyant incomparison to the bitumen product.

A standard bitumen of penetration grade 60/70 1/10mm at 25° C., heatedup to about 90° C., was poured into 5 of the containers. The containerswere sealed and left to cool down to ambient temperature for 24 hours.The five containers were subsequently placed into a heating vessel ofapproximately 50 liter capacity where the temperature was raised toabout 140° C. by means of electrical coils. The observation of thisexperiment was that the packaging material melted together with itscontent of bitumen. After about three hours time, the whole of thebitumen and its packaging was melted and there was hardly detectablepackaging material floating at the surface of the heating vessel. Basedon the above, there was only about 0.25 wt % of iron oxide added tofinal molten bitumen. The whole of the molten material was subsequentlygently stirred for two minutes to ensure homogeneity. Uponhomogenization, a sample of the mixture was taken and tested against asample of the same neat bitumen having undergone the same heat treatmentbut without packaging material. The results are shown in Table 1. TABLE1 Test results on bitumen specimens Neat Packaged Test Method UnitTypical Bitumen Bitumen Penetration at 25° C. ASTM D5 0.1 mm 60 to 70 6061 Softening point ASTM D36 ° C. 44 to 57 48.6 51.0 Viscosity at 135° C.ASTM D445 cSt nil 429.8 451.2 Ductility at 25° C. ASTM D13cm >100 >100 >100 Flash point, COC ASTM D92 ° C. >232 344 342 Solubilityin trichoroethylene ASTM D2042 % >99 99.91 99.67 Thin Film Oven TestASTM D1754 Mass loss % <1.0 0.05 0.03 Retained penetration % >55 65.564.3

The results of Table 1 indicate that there is no adverse effect of thepackaging material on the packaged bitumen, which maintains itscharacteristics well within the specifications of most applications. Thesolubility in trichloroethylene is also well maintained within usualspecifications. The decrease in solubility reflects the amount of ironoxide added to the packaging material and this does not impair theoverall characteristics of the sample tested. The increase in softeningpoint, arguably due to the addition of the polymer contained in thepackaging material, can actually be considered as an improvement, as itis indicative of a befter performance of bitumen at elevatedtemperature.

EXAMPLE 2 Calcium Carbonate as the Metallic Material

A second packaging material composition for bitumen product was preparedwith the following and had the following characteristics (where “sp.gr.” refers to specific gravity): Ethylene vinyl acetate copolymer, MIof 35 g/10 min, 72% sp. gr of 0.94 Bitumen grade 60/70, sp. gr. of 1.0315% Calcium carbonate, industrial grade, sp. gr. of 2.70 13% Theoreticalspecific gravity:  1.18 Measured specific gravity by hydrostaticbalance:  1.06

The ethylene vinyl acetate, bitumen, and calcium carbonate componentswere thoroughly mixed together at a temperature of approximately 200° C.for three hours to enable for the highest possible dispersion of theingredients into each other. The resulting material was processedthrough the same experiment as described above and was used to packagebitumen of penetration 60/70. The conclusion of the test was similar tothat of Example 1. There was no significant amount of packaging materialfloating at the surface of the melting vessel upon the full meltingprocess of the packaged bitumen.

All references cited herein, including patents, patent applications, andpublications, are hereby incorporated by reference in their entireties,whether previously specifically incorporated or not.

Having now fully described this invention, it will be appreciated bythose skilled in the art that the same can be performed within a widerange of equivalent parameters, concentrations, and conditions withoutdeparting from the spirit and scope of the invention and without undueexperimentation. The invention also includes all of the steps, features,compositions and compounds referred to or indicated in thisspecification (unless specifically excluded) individually, collectively,and any and all combinations of any two or more of said steps orfeatures.

While this invention has been described in connection with specificembodiments thereof, it will be understood that it is capable of furthermodifications. This application is intended to cover any variations,uses, or adaptations of the invention following, in general, theprinciples of the invention and including such departures from thepresent disclosure as come within known or customary practice within theart to which the invention pertains and as may be applied to theessential features hereinbefore set forth.

1. A consumable container for use in transport and/or melt-processingoperations, or a film suitable for use in packaging, said container orfilm composed of a composition comprising: i) 60.1% to 99.9% by weightof a moldable material composed of a plastic or polymer material wherein0.1% to 39.9% of said 60.1% to 99.9% is bituminous material; and ii)0.1% to 39.9% by weight of a dense metallic material.
 2. A container orfilm according to claim 1, wherein the plastic or polymer material isselected from polyethylene, polypropylene, polystyrene,styrene-butadiene-styrene, styrene-butadiene, styrene-indene-styrene,copolymers of acrylates and methacrylates, ethylene-vinyl-acetate,atactic polypropylene, mineral or natural or synthetic fibers, andmixtures thereof.
 3. A container or film according to claim 1 or 2,wherein the plastic or polymer material is an ethylene-vinyl-acetatecopolymer.
 4. A container or film according to claim 1, 2 or 3, whereinthe bituminous material is selected from bitumen, oxidized bitumen,semi-blown bitumen, natural occurring bitumen, refinery heavy residues,heavy fuel-oil, extracts, petroleum-tar, coal-tar, aromatic extracts,synthetic resins, natural resins and mixtures thereof.
 5. A container orfilm according to any one of the preceding claims wherein the metallicmaterial is a source of metal ions derived from at least one metal orthe salts and oxides thereof and/or a metal complex.
 6. A container orfilm according to any one of the preceding claims, wherein the metallicmaterial is in a powder, pellet or granular form.
 7. A container or filmaccording to claim 5 or 6, wherein the metallic material is or comprisesiron, calcium, an iron oxide, calcium carbonate, a silicate, zinc, zincsulfate, or mixtures thereof.
 8. A composition comprising: i) 60.1% to99.9% by weight of a moldable material composed of a plastic or polymermaterial wherein 0.1% to 39.9% of said 60.1% to 99.9% is bituminousmaterial; and ii) 0.1% to 39.9% by weight of a dense metallic materialselected from iron oxide, zinc sulfate, crushed stone, and glass fibers,or a dense metallic material comprising zinc.
 9. A compositioncomprising: i) about 90% by weight of a moldable material composed ofabout 83% of an ethylene-vinyl-acetate copolymer and about 17% ofbituminous material; and ii) about 10% by weight of iron oxide.
 10. Aconsumable container for use in transport and/or melt-processingoperations according to any one of claims 1-7.
 11. A consumablecontainer according to claim 10, further comprising a bitumen productcontained in said container, wherein the specific gravity of thecomposition is equal to or greater than the specific gravity of thebitumen product contained therein at the melting temperature of thebitumen product.
 12. A consumable container according to claims 10 or11, wherein the container is formed by blow-molding, casting, injectionmolding, the use of a forming apparatus, or combinations thereof.
 13. Aconsumable container according to any one of claims 10-12, in the formof a sealable bag, barrel, box, bowl, or cylinder of any suitable shapeor size.
 14. A film suitable for use in packaging according to any oneof claims 1-7.
 15. A composition according to claim 8 wherein said densemetallic material is iron oxide.
 16. A composition according to claim 8or 15 wherein said moldable material composed of a plastic or polymermaterial is an ethylene-vinyl-acetate copolymer.
 17. A compositioncomprising: i) 60.1% to 99.9% by weight of a moldable material composedof an ethylene-vinyl-acetate copolymer wherein 0.1% to 39.9% of said60.1% to 99.9% is bituminous material; and ii) 0.1% to 39.9% by weightof a dense metallic material.